Biomaterial Database

Room temperature magnetization switching in topological insulator-ferromagnet heterostructures by spin-orbit torques. 2017

Yi Wang, and Dapeng Zhu, and Yang Wu, and Yumeng Yang, and Jiawei Yu, and Rajagopalan Ramaswamy, and Rahul Mishra, and Shuyuan Shi, and Mehrdad Elyasi, and Kie-Leong Teo, and Yihong Wu, and Hyunsoo Yang

Department of Electrical and Computer Engineering, National University of Singapore, Singapore, 117576, Singapore.

Topological insulators with spin-momentum-locked topological surface states are expected to exhibit a giant spin-orbit torque in the topological insulator/ferromagnet systems. To date, the topological insulator spin-orbit torque-driven magnetization switching is solely reported in a Cr-doped topological insulator at 1.9 K. Here we directly show giant spin-orbit torque-driven magnetization switching in a Bi2Se3/NiFe heterostructure at room temperature captured using a magneto-optic Kerr effect microscope. We identify a large charge-to-spin conversion efficiency of ~1-1.75 in the thin Bi2Se3 films, where the topological surface states are dominant. In addition, we find the current density required for the magnetization switching is extremely low, ~6 × 105 A cm-2, which is one to two orders of magnitude smaller than that with heavy metals. Our demonstration of room temperature magnetization switching of a conventional 3d ferromagnet using Bi2Se3 may lead to potential innovations in topological insulator-based spintronic applications.